Pumps



3 Sheets-Sheet 1 E. WILLIAMS PUMPS June 17, 1958 7 Filed May 13. 1955 Filed May 13, 1955 E. WILLIAMS 2,839,002

PUMPS 3 Sheets-Sheet 2 w T g 11 Q k m 1 /-f @uazvtop WILLIAMS June17,

PUMPS 5 Sheets-g 3 Filed m 13' 55 2,839,002 1 rumrs Ernest Williams, Tunbridge Wells, England Application May 13, 1955, Serial No; 508,284 Claims priority, application Great Britain May 13, 1954 8 Claims. Cl. 103-37 This invention relates to pumps and more particularly to pumps of the kind using a hydraulically operated diaphragm or bellows such as are used for pumping either liquids or gases.

The invention has for its main object to provide an improved form of pump of this character and the invention accordingly consists in a pump mechanism for pumping liquids or gases wherein the pump action is effected by a hydraulically actuated diaphragm or bellows controlled by a reciprocating plunger, and wherein means are provided for releasing the pressure of the actuating fluid at United States Patch t least once in each cycle of the pump movement and for adjusting the point in the. pump cycle at which such pressure release occurs so as to bring about a corresponding variation inthe effective capacity of the pump.

According to the preferred arrangement, the hydraulic fluid which actuates the diaphragm or bellows in response I to the pump is adapted to communicate to atmosphere through one or more port openings so arranged as to be automatically closed by the pump plunger during its stroke so asto render thev pump operative, means being provided for adjusting either manually or automatically the position at which the closure of-said port openings is effected in the pump stroke so as to vary the effective movement of-the diaphragm or bellows in response to each stroke of the pump and thereby vary the pump capacity.

The invention will be more completely understood from the'following detaileddescription which is given in conjunction with the accompanying drawings, in which:

Figures 1 and 2are sectional side and end views respectively of a diaphragm pump constructed in accordance with the invention, and V 7 Figure 3 isa sectional side view of a modified form of diaphragm pump. a

Referring first to Figures 1 and 2 of these drawings, I construct my improved hydraulically operated pump with a diaphragm 1 0f any'well known form which is secured across a chamber 2 so that one side is in contact with the actuating fluid while the other side is in contact with the fluid to be pumped and which may be arranged to be drawn through a suction opening 3 and expelled through a delivery opening 4 in response to the reciprocating movements of the diaphragm in any suitable well ;known manner, the actuating fluid contacting the diaphragm througha set of apertures 5 in a fluid distributor plate 6, and the fluidtp be pumped contacting the diaphragm through a set of apertures 7 in a diaphragm draulic fluid and which communicates with the actuating side of the diaphragm 1. This forward part of the plunger is of hollow cylindrical form and the exterior wall is stepped in such a way that the rear part 13 forms a close fit with the interior wall of the fluid chamber 12 while the front part 14 forms an annular space 15 between its outer wall and the inner wall of the fluid chamber 12, and a plurality of ports 16 are provided in the wall of this part of the plunger so that the interior of the plunger may communicate with the aforesaid annular space 15 through these ports. The interior of the plunger is closed at its forward end by a cylindrical shaped shaft 17 which is mounted coaxially with respect to the plunger so that the latter slides over this shaft during its movement and forms a close fit over it. This hollow end part of the plunger is secured to the main part of the plunger by an annular cup member 18 through which one or more passages extend to the interior of the hollow part of the plunger and by means of which such interior communicates through a passage 19 with a fluid reservoir 20 which communicates with atmosphere or with a chamber of sufficient volume to'prevent an appreciable increase in pressure so that when the aforesaid ports 16 in the wall 'of the plunger are open, the fluid in the pump will be substantially at atmospheric pressure, but that when these ports are sealed by the aforesaid cylindrical shaft17, the fluid pressure can build up under the action of the pump and operate the diaphragm. This cylindrical shaft 17 over which the hollow end part of the plunger slides, is so arranged that the aforesaid ports 16 are open during part of each stroke of the plunger so that the fluid pressure in the pump is released to atmospheric pressure once during each stroke of the plunger.

It will be appreciated that with this arrangement, the effective movement of the diaphragm and the consequent pump capacity will depend upon the position of the plunger during its forward or backwardmovement at which the fluid ports 16 are closed or opened by the presence of the cylindrical shaft 17, andin order that the pump capacity may be varied, therefore, this cylindrical shaft is mounted for longitudinal adjustment so that its position relative to the fluid ports in the plunger may be varied. Conveniently, this cylindrical shaft is slidably mounted and controlled by a screw threaded actuating member 21 which is arranged to co-operate with a rotatable hand wheel 22 which is preferably provided with a Vernier or other graduated scale for indicating its position.

Thus by rotating this hand wheel, the position of the cylindrical shaft 17 and the consequent pump capacity may be varied as desired, andthis variation can be effected air release valve 23 is provided which is conveniently arranged in the fluid reservoir 20 and is connected with the fluid space in the pump so that as the fluid pressure is increased by the pump action, the air is exhausted through the air relief valve, and in the event of any fluid escaping at the same time, it will be automatically discharged into the fluid reservoir. Conveniently, this air release valve is mounted at the highest point of a passageway 24 which communicates with the fluid space at the forward end of the pump plunger through one or more ports or apertures 28 in the wall of the cylindrical chamber in which the plunger reciprocates.

In order to relieve or reduce the fluid pressure in the pump during the time that the ports 16 in the pump plunger are closed so as to prevent the fluid pressure from rising above a predetermined value at any time in the pump cycle, a relief valve 25 is provided which is spring loaded by a helical spring 26 the tension of which may be adjusted by the screw threaded control member 27.

If desired, the setting of the pump capacity may be cont olled automati ly by a p st n o aphra m coupled to a pneumatic or hydraulic proportional or similar controller. One such arrangement is shown in Figure 3 in which e fo w nd o the pump p u er is hown together with the fluid chamber and associated parts, while on h ight ha de f he figure a rm of apparatus is shown for automatically effecting the positioning of the shaft 17 in relation to the stroke of the plunger. This apparatus comprises a piston 30, which operates in a fluid chamber 31, and acts upon the shaft 17 through a piston rod 32, the piston being spring loaded by the helical spring 33. The fluid chamber 31 communisates w a ppe h m e by a p sage n the upper part or cover of this upper chamber is provided with an air inlet 36 which communicates with the outlet from a pressure control instrument 37 of any suitable known form having a bellows 38 connected by a suitable linkage 39 with an arm or bracket 40 secured to the end of the shaft 17. The control instrument 37 is such that wh n the P ssur s pp i to he in r me t s in e ed, he b l s 8 op a s o ope a valve c n r lli h outlet pressure, thus forcing air through the outlet into e. uppe a be 3 n r as e flu d pr sure on the plunger 30 which thus moves to the left against the action of the spring 33, and alters the position of the shaft '17. When the controlling pressure is released, the reverse action takes place, the piston moving back under the action of its r storing spring. A manually operated handjack 41 is also provided for limiting the return position of the piston, this handjack being secured to a shaft 412 which is screwed into the casing 43 so that the end of the shaft provides a limit stop for the piston, the position of the stop being varied by rotation of the handjack.

It is to be understood however that the invention is not to be regarded as being limited to the particular constructional arrangements hereinbefore described and illustrated, and that the hydraulically operated diaphragm may, if desired, be substituted by a bellows of any suitable or Well known form.

It is also to be understood that any number of pumps can be arranged to be controlled by one instrument, and that by the adjustment of the length of the control stroke of each. unit, the instrument may be made to vary the capacity of the pumps in predetermined proportions, thus ensuring the same mixture from zero flow to full capacity. Conveniently, the mechanism is so arranged that in case offailure of the operating medium, the pumps will return to zero stroke when the handjack provided can be used for manual control.

A pump as described'above is thus particularly suitable for pumping either liquids, or gases in manufacturing processes where a pump is required which can be, used with maximum efliciency without danger of bursting the diaphragm or bellows, and the pump, as, hereinbefore described, not only fulfils this requirement, but also possesses the advantage that it enables the pump capacity to be readily varied to suit the particular process to which it is applied.

I claim:

1. A pump mechanism comprising a hydraulically operable diaphragm for pumping liquids or gases, a hollow plunger for acting upon the hydraulic fluid controlling said diaphragm, means for causing said plunger to carry out reciprocating movements, a passage extending from the fluid space through the interior of said plunger to a reservoir at atmospheric pressure, a control member o er which said hollo p unger slides du ing ts e ip cating movements, said plunger being provided with port openings which form part of said passage and which are closed by said control member during the application of pressure to said diaphragm but which are uncovered during part of the stroke of the plunger whereby the fluid pressure is released at least once during each cycle of the pump, and means for adjusting the position of said control member with respect to said plunger so as to vary the pointin the stroke of the plunger at which said port openings are uncovered and thereby effect a corresponding variation in the effective capacity of the pump.

2. A pump mechanism according to claim 1 and com prising manually operated actuating means for adjusting the position in the stroke of the plunger at which the closure of said port openings is eflected.

3. A pump mechanism according to claim 1 and comprising means for automatically setting the position in the stroke of the plunger at which the closure of said port openings is effected.

4. A pump mechanism according to claim 1, wherein the forward part of the pump plunger is of tubular form having one or more port openings through which the hydraulic fluid which actuates the diaphragm in response to the pump communicates to atmosphere, and wherein a rod member is provided over which the tubular end part of said plunger is slidably arranged, said rod member being so positioned that said port openings are automatically closed during part of the stroke of the plunger, and opened during the remainder of such stroke.

5. A pump mechanism according to claim 4 and comprising means for adjusting the position of said rod member so as to vary the point in the pump stroke at which said port openings are uncovered.

6. A pump mechanism according to claim 5, wherein said means comprises a screw threaded manually operable control device which is operatively associated with said rod member so as to var-y the position of said rod member longitudinally.

7. A pump mechanism according to claim 5, wherein said means comprises a piston member operatively associated with said rod or shaft and operable in response to a' change of fluid pressure derived from a pressure control device.

8. A pump mechanism according to claim 7, wherein said pressure control device comprises an air operated control mechanism which communicates with a fluid chamber associated with the actuating side of said piston, said control mechanism comprising a bellows which operates in response to a change of pressure and which is operatively connected by a linkage mechanism with said rod member.

References Cited in the file of this patent UNITED STATES PATENTS 1,584,449 Grut-z ner May 11, 1926 1,650,377 Nixon Novl 22, 1927 1,782,144 Jensen Nov. 18, 1930 1,927,587 Hacker Sept. 19, 1933 2,195,037 Petty Mar. 26, 1940 2,303,597 Adelson Dec. 1, 1942 2,371,787 Ward Mar. 20, 1945 2,543,828 Brown Mar. 6, 1951 2,603,158 Nemetz July 15, 1952 

